Early Left and Right Ventricular Response to Aortic Valve Replacement

Area of Science:

• Cardiology
• Cardiac Surgery
• Echocardiography

Background:

• The immediate impact of aortic valve replacement (AVR) on myocardial function in aortic stenosis patients is not fully understood.
• Potential effects include impaired left ventricular (LV) function due to cardioplegia and ischemia-reperfusion, or improved function from afterload reduction.
• Right ventricular (RV) function may be negatively affected by cardioplegic arrest without loading condition benefits.

Purpose of the Study:

• To investigate the intraoperative effects of AVR on LV myocardial function using echocardiographic strain measures.
• To evaluate the impact of AVR on RV function during the perioperative period.

Main Methods:

• A supplementary analysis of 97 patients undergoing AVR for aortic stenosis from a clinical trial.
• Standardized intraoperative transesophageal echocardiography assessed LV and RV systolic and diastolic function before incision and after chest closure.
• Two-dimensional speckle-tracking echocardiography analyzed global longitudinal myocardial strain and strain rate.

Main Results:

• LV systolic strain rate improved post-AVR (P < 0.001), while LV global longitudinal strain showed no significant change (P = 0.07).
• RV systolic strain significantly worsened post-AVR (P < 0.001), whereas RV systolic strain rate remained unchanged (P = 0.83).
• Hemodynamic changes included decreased LV volumes and blood pressure, and increased heart rate at surgery's end.

Conclusions:

• Aortic valve replacement improves left ventricular function, evidenced by enhanced longitudinal strain rate.
• Right ventricular function, assessed by longitudinal strain, is reduced after aortic valve replacement.